Shipping Container Having a Flame Retardant Layer and a Thermal Blocking Layer

ABSTRACT

A shipping container for shipping thermally active materials includes a plurality of structural panels that define a container interior, and are configured for receiving the thermally active materials. The container also includes an exterior disposed adjacent to an environment in which the shipping container is disposed. A thermal barrier member is placeable between the thermally active materials and the environment in which the container is placed. The thermal barrier includes a thermal barrier interior panel and a thermal barrier external panel defining a heat absorbing material receiving cavity. A flowable polymer based heat absorbing material is disposed within the heat absorbing material receiving cavity. The thermal barrier is configured to substantially surround the thermally active materials to reduce the passage of thermal energy between the thermally active materials and the environment in which the shipping container is disposed.

BACKGROUND

Billions of lithium batteries are shipped every year as cargo.Transportation of lithium batteries can be a risky task, especially inthe case of shipment on board an aircraft. The term “lithium battery”refers to a class of batteries that include cathodes or electrolytesthat contain either metallic lithium or a lithium compound. In general,lithium batters come in two types of categories that include lithiummetal batteries and lithium-ion batteries. Lithium metal batteries arenot rechargeable and used in such devices a camcorders, cameras, and soforth. Lithium-ion batteries are rechargeable and are used in numerousproducts.

Lithium batteries are currently classified as Class 9 materials underthe Hazardous Materials Regulations (“HMR”). Nonetheless, most lithiumbatteries and devices are excepted from the Class 9 provisions of theHMR. Because of this exception, they do not require a Notice to thePilot in Command to alert the crew of their presence on-board anaircraft. However, there are still marking, labelling, and shippingdocument requirements that must be met in order to comply. Some lithiumbatteries are not excepted and require more stringent shippingrequirements when transported by air.

A problem has arisen as the volume of shipments of lithium batteries hasexploded over the last decade. Lithium batteries are prone to energeticfailures (fire and/or explosion) that can occur for any number ofreasons. Testing conducted by the FAA William J. Hughes Technical Center(“FAA Tech Center”) indicates that particular propagationcharacteristics are associated with lithium batteries. Overheating hasthe potential to create thermal runaway, a chain reaction leading toself-heating and release of a battery's stored energy. In a firesituation, the air temperature in a cargo compartment fire may be abovethe auto-ignition temperature of lithium. For this reason, batteriesthat are not involved in an initial fire may ignite and propagate, thuscreating a risk of a catastrophic event.

Failures in lithium batteries that can lead to fires occur for manyreasons. These reasons could include poor design, manufacturing flaws,external damage, poor battery pack designs, insufficient or inadequateprotection design, and overcharging. Thermal runaway can also lead tothe failure of a lithium battery. As such, a need exists for a way toship lithium batteries in a safe and efficient manner that will protectthe vehicle shipping the batteries, for example a cargo plane, fromlithium battery failures that could cause fires and result in acatastrophic event.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a portion of the shipping container disclosed herein.

FIG. 2 illustrates a lid for the shipping container disclosed herein.

FIG. 3 illustrates the molecular makeup of an outer layer of thecontainer.

FIG. 4 illustrates a paste holding member.

FIG. 5 illustrates a cross-sectional view of a panel used in thecontainer.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended. Any such alterations and furthermodifications in the illustrated devices, and such further applicationsof the principles of the invention as illustrated herein arecontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Referring to FIG. 1, a shipping container 10 is illustrated that isdesigned to house articles that may be flammable during shipping, suchas, by way of example, lithium-ion batteries. As illustrated, theshipping container 10 includes an outer housing 11 that comprises fourvertical outer walls 12 a-d and a horizontal lower wall 12 e. Arespective end of vertical wall 12 a is connected with an end ofvertical wall 12 b and another end of vertical wall 12 a is connectedwith an end of vertical wall 12 d. Another end of vertical wall 12 b isconnected with an end of vertical wall 12 c. The other end of verticalwall 12 c is connected with an end of vertical wall 12 d. The horizontallower wall 12 e includes four ends that are connected with each of thefour vertical walls 12 a-d. The four vertical walls 12 a-d and thehorizontal lower wall 12 e of the shipping container 10 define aninterior cavity 14 in which items can be placed for shipping such as,for example, lithium batteries.

Referring to FIG. 2, a lid 16 of the container 10 is illustrated that issized and configured to fit over the top of the four vertical walls 12a-d. In one form, the lid 16 is sized such that a small gap existsbetween the four vertical walls 12 a-d and four side walls 18 a-d of thelid 16. As illustrated, the four side walls 18 a-d are interconnectedwith one another to form a rectangular shaped member. The small gapallows a certain amount of gas to exit or vent from an interior cavity14 (as defined below) while still allowing the lid 16 to be secured tothe vertical side walls 12 a-d. In the case of a lithium-ion batteryfire, for example, a pressure pulse may be given off when batteriesexplode and the gas and pressure created by the pressure pulse must beable to escape the container 10 in order to ensure that the container 10is not compromised by the pressure pulse. As further illustrated, thelid 16 includes a top cover 18 e that is connected with the four sidewalls 18 a-d.

Referring to FIGS. 1 and 2, in one form the four vertical walls 12 a-d,horizontal lower wall 12 e, side walls 18 a-d, and top cover 18 e aremanufactured from chipboard. Chipboard is an engineered wood productthat is typically manufactured from wood chips, sawmill shavings, oreven sawdust, and a synthetic resin or other suitable binder, which ispressed and extruded. In one form, the binder is configured to absorbwater molecules. Referring to FIG. 3, during manufacturing of thecontainer 10, a fire retardant 20 is infused into the chipboard 22 thatis used to form the outer layer 11 of the container 10. As illustratedin FIG. 3, the chipboard 22 includes a plurality of chipboard molecules24 that have been infused with a plurality of flame retardant molecules26.

In the preferred form, the fire retardant 20 is a non-toxic,non-hazardous fire retardant designed for unsealed natural fibermaterials and products, such as, chipboard 22. The preferential fireretardant 20 is manufactured by NoChar, Inc. under the trademarkNochar's Fire Preventer (“NFP”). NFP may be applied to the chipboard 22by spray, curtain coating, thermal dip, vacuum chamber, roller coating,or soaking. NFP is a water-soluble product that uses water as a carrierto penetrate the chipboard 22. The water is then dried or driven off,leaving the actual flame retardant 20 in place in the chipboard 22. NFPincreases the fire safety of materials and products treated byincreasing the temperature required for ignition, reducing the rate ofheat release after ignition, and slows the rate of flame spread. NFP canbe added to bonding agents, adhesives, and sealants.

Referring to FIG. 1, the container 10 includes an inner housing 30 thatis used to line the interior structure defined by the outer layer 11. Asillustrated, the inner housing 30 comprises four vertical side panels 32a-d and a lower panel 32 e. The vertical side panels 32 a-d resideadjacent to corresponding respective vertical walls 12 a-d. The lowerpanel 32 e is positioned underneath or adjacent to a lower portion ofthe vertical side panels 32 a-d. A top panel 32 f is removably connectedwith an upper portion of the vertical side walls 32 a-d. The verticalside panels 32 a-d and lower panel 32 e define the interior cavity 14where cargo to be shipped may be placed. Once the top panel 32 f ispositioned in place after the cargo is loaded into the interior cavity14, the lid 16 can be positioned over the top of the container 10.

Referring to FIGS. 4 and 5, the panels 32 a-f disclosed herein areconfigured to resist becoming ignited and to contain any fire that maybreak out in the cargo placed in the internal cavity 14 until itextinguishes on its own or burns itself out. In one form, the panels 32a-f include a crate or paste holding member 40. As illustrated, thepaste holding member 40 includes a plurality of cells 42 that aredefined by a first cell defining member 44 and a second cell definingmember 46. In the illustrated form, the first and second cell definingmembers 44, 46 are oriented in a horizontal and vertical configurationthereby forming rectangular shaped cells 42. In other forms, the firstand second cell defining members 44, 46 may take other orientationsthereby forming cells 42 having different shapes. In other forms, thepanels 32 a-f could be placed on the outside of the container 10 andmultiple layers of outer layers could be used.

Referring to FIG. 4, the cells 42 are each filled with a thermalblocking paste 48. Although only four cells 42 are illustrated as beingfilled with the thermal blocking paste 48 in this form, it should beappreciated that every cell 42 in the paste holding member 40 would befilled with the thermal blocking paste 48. The thermal blocking paste 48is configured to minimize direct or radiant heat transfer from adjoiningsurfaces. As such, during operation, the thermal blocking paste 48inhibits heat from a fire inside the internal cavity 14 fromtransferring from the panels 32 a-f to the vertical side walls 12 a-d,the horizontal lower wall 12 e, and the top cover 18 e of the container10. In the preferred form, the thermal blocking paste 48 is manufacturedby Nochar, Inc. under the “nochar's P215” trademark.

Referring to FIG. 5, a cross-sectional view of a representative panel 32a-f is depicted. The paste holding member 40 is surrounded by a firstfire resistant layer of material 50. Referring to FIG. 1, respectivecorners 52 and edges 54 of the panels 32 a-e are secured together by asecond fire resistant layer of material 56 thereby forming the internalcavity 14. The second fire resistant layer of material 56 helps ensurethat flames from any fire within the internal cavity 14 will not reachthe vertical walls 12 a-d or lower wall 12 e of the outer layer 11 ofthe container 10. It should be appreciated that in other forms, thevertical panels 32 a-d and the lower panel 32 e may be formed as oneintegral unit thereby eliminating the need for the second fire resistantlayer of material 56.

During initial testing of the container 10, unexpected results wereobtained as it relates to the ability of the container 10 to contain afire. It has been reported that lithium-ion batteries ignite at about953° F. and can reach temperatures that exceed 1100° F. while burning.During tests of the container 10 disclosed herein, fires exceeding 1400°F. have been introduced into the internal cavity 14 and the container 10was sealed for 20 minutes, 40 minutes, and 60 minutes while the fireswere left to burn themselves out. In particular, road flares, which donot require oxygen to burn, were introduced into the internal cavity 14.After the tests were conducted, while there was burn marks on the fireresistant layers of material 50, 56 the panels 32 a-f were capable ofprohibiting any burning of the outer layer 11 of the container 10. Assuch, all of the flames from the fire were contained within the interiorcavity of the container 10. Thus, the container 10 disclosed herein iscapable of prohibiting lithium-ion battery fires ignited within theinternal cavity 14 from spreading beyond the container 10 therebyincreasing the safety of shipping lithium-ion batteries.

Although various embodiments have been described as having particularfeatures and/or combinations of components, other embodiments arepossible having a combination of any features and/or components from anyof embodiments as discussed above. As used in this specification, thesingular forms “a,” an and the include plural referents unless thecontext clearly dictates otherwise.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatall changes and modifications that come within the spirit of theinvention are desired to be protected.

What is claimed is:
 1. A shipping container configured for shippingthermally active materials, the shipping container comprising aplurality of structural panels defining a container interior configuredfor receiving the thermally active materials, and an exterior disposedadjacent to an environment in which the shipping container is placed, athermal barrier member for placement between the thermally activematerials and the environment in which a container is placed, thethermal barrier including a thermal barrier interior panel, and athermal barrier exterior panel defining a heat absorbing materialreceiving cavity, and a flowable, polymer based heat absorbing materialdisposed within the heat absorbing material receiving cavity, whereinthe thermal barrier is configured to substantially surround thethermally active materials to reduce the passage of thermal energybetween the thermally active materials and the environment in which theshipping container is disposed.
 2. The shipping container of claim 1further comprising a pressure relief member for permitting pressuregenerated by the thermally active materials to be vented to atmosphere.3. The shipping container of claim 2 wherein the pressure relief membercomprises at least one of a pressure relief valve and a gap in thethermal barrier member through which gas can pass in an over pressurecondition.
 4. The shipping container of claim 1 wherein the thermalbarrier includes a partition member disposed within the heat absorbingmaterials receiving cavity, the partition member defining a series ofcells configured for receiving and holding the flowable polymer basedheat absorbing material.
 5. The shipping container of claim 4 whereinthe partition member extends generally throughout the entire heatabsorbing material receiving cavity for maintaining the flowable polymerbased heat absorbing material dispersed generally consistentlythroughout the heat absorbing material receiving cavity.
 6. The shippingcontainer of claim 5 wherein the partition member comprises a honeycombcell structure disposed within substantially the entire heat absorbingmaterial receiving cavity, the honeycomb cell structure partition memberbeing configured for receiving the flowable polymer based heat absorbingmaterial within the cells for generally evenly dispensing the polymerbased heat absorbing material throughout the heat absorbing materialreceiving cavity.
 7. The shipping container of claim 1 wherein thestructural panels include a base panel member, at least one first sidepanel member coupled to the base panel member, and a top panel membermovable between an open and a closed position, and wherein each of thebase panel member, at least one first side panel members and top panelmember include an interior surface.
 8. The shipping container of claim 7wherein the thermal barrier member includes a plurality of thermalbarrier panels including a base thermal barrier panel disposed adjacentto the interior surface of the base panel member, at least one sidethermal barrier panel disposed adjacent to the interior surface of theat least one side panel member, and a top thermal barrier panel disposedadjacent to the interior surface of the top panel member, the pluralityof thermal barrier panels being configured for defining a thermallyactive material containing space substantially surrounded by theplurality of thermal barrier panels for reducing the passage of heatacross and exteriorly of the thermal barrier panels.
 9. The shippingcontainer of claim 1 wherein the thermally active materials comprisecombustible materials capable of engaging in a sustained burning, andigniting if the temperature of the combustible material exceeds acombustion threshold value, wherein the thermal barrier member providesa sufficient thermal barrier so as to maintain the environment in whichthe shipping container is placed at a temperature below the combustionthreshold value during a sustained burning of combustible materialsdisposed interiorly of the thermal barrier member.
 10. The shippingcontainer of claim 9 wherein the combustible materials comprise lithiumbatteries, and wherein the thermal barrier member provides a sufficientthermal barrier to maintain the environment in which the shippingcontainer is placed at below about 950 degrees F. during a sustainedburning of the lithium batteries disposed interiorly of the thermalbarrier members.
 11. The shipping container of claim 1 wherein thethermally active materials comprise lithium batteries, and where thethermal barrier member is capable of maintaining the environment inwhich the shipping container is disposed at less than about 950 degreesF. during a sustained burning of the lithium batteries disposed withinthe container interiorly of the thermal barrier.
 12. The shippingcontainer of claim 1 wherein the lithium batteries comprise at least oneof lithium batteries and lithium ion batteries.
 13. The shippingcontainer of claim 1, wherein the polymer-based heat absorbing materialcomprises a superabsorbent polymer.
 14. The shipping container of claim13, wherein the superabsorbent polymer is hydrated with water.
 15. Theshipping container according to claim 13, wherein the superabsorbentpolymer is a homopolymer.
 16. The shipping container according to claim15, wherein the homopolymer is a polyacrylate or polyacrylamide.
 17. Theshipping container according to claim 14, wherein the superabsorbentpolymer is a copolymer.
 18. The shipping container according to claim17, wherein the copolymer is a polyacrylate/polyacrylamide copolymer.19. The shipping container according to claim 14, wherein thesuperabsorbent polymer is cross-linked.
 20. The shipping containeraccording to claim 19, wherein the superabsorbent polymer iscross-linked with an oil.
 21. The shipping container according to claim20, wherein the oil is a mineral oil.
 22. The shipping containeraccording to claim 14, wherein the superabsorbent polymer is formulatedas an emulsion.
 23. The shipping container according claim 22, whereinthe emulsion comprises water and an oil.
 24. The shipping containeraccording claim 23, wherein the oil is a mineral oil.
 25. The shippingcontainer according claim 22, wherein the emulsion comprises water, oil,and superabsorbent polymer cross-linked with mineral oil.
 26. Theshipping container according to claim 14, wherein the superabsorbentpolymer is formulated as a paste.
 27. The shipping container of claim26, wherein the paste comprises oil and water.
 28. The shippingcontainer of claim 27, wherein the oil is a mineral oil.
 29. Theshipping container of claim 27, wherein the paste comprises water, oil,and superabsorbent polymer cross-linked with mineral oil.
 30. Theshipping container of claim 1, wherein the polymer-based heat absorbingmaterial is NOCHAR's P215™.